Transplantation of human iPSC-derived NPCs results in an increased rat host immune response and expression of TN-C over time. Tissue surrounding the graft sites was analyzed using IHC for expression of IBA-1 and GFAP (indicated by white arrows in A-T) alongside either HuNu and hNCAM to identify the graft site. At early time points of 2 weeks (A,C—low magnification; B,D—high magnification), IBA-1 staining is mildly increased compared to control tissue (I). However, over time there is a noticeable increased immune response from microglia surrounding the HuNu-positive graft site (K,M—low magnification; L,N—high magnification) compared to control tissue (S). Similarly, GFAP staining is mildly increased at earlier time point of 2 weeks (E,G—low magnification; F,H—high magnification) compared to control tissue (J). Over time this expression is markedly increased (O,Q—low magnification; P,R—high magnification) compared to control tissue (T). Following transplantation of hNPCs there was a localized upregulation of TN-C at the graft site (U–W). Scale bar in (A,C,E,G) = 250 μm; (B,D,F,H–J,L,N,P,R–T,W) = 150 μm; (K,M,O,Q,U,V) = 500 μm.